JP6680480B2 - Ethylene polymer and hollow molded article - Google Patents

Description

  The present invention relates to an ethylene polymer which is particularly excellent in appearance and moldability and mechanical strength as compared with a conventionally known ethylene polymer, and a hollow molded product formed from the same.

  Generally, a blow container such as a high density polyethylene typified by a gasoline tank, a drum can, and a chemical can is manufactured by a blow molding method. In the blow molding method, an ethylene polymer is melted by an extruder and extruded into a cylindrical parison, and the extruded parison is sandwiched between molds and blown with a pressurized gas from a blow pin to expand and deform the parison, thereby forming a gold mold. The mold is shaped into a cavity in the mold and then cooled. Such a blow molding method can be widely applied to gasoline tanks, drums, chemical cans, and even panel-shaped molded products having complicated shapes, and is also widely used in the industrial field because molding is simple.

  Conventionally, metal fuel tanks have been used as fuel tanks for internal combustion engines such as automobiles, but in recent years, in combination with the background of the need for weight reduction for energy saving, rust does not occur and it is molded into a desired shape. Plastic fuel tanks have come to be used because they are easy to operate. In addition, there has been an increasing demand for further weight reduction of plastic drums and chemical cans for the purpose of saving energy and improving handleability.

  In order to meet the ever-increasing needs for thinning, extremely high material properties are required for plastic hollow moldings. That is, it is required to have good appearance and moldability, and have long-term fatigue characteristics such as good impact resistance and good environmental stress crack resistance and creep resistance.

  Patent Document 1 discloses a polyethylene composition suitable for blow molding of a gasoline tank. This composition consists of a blend of a high molecular weight polymer and a low molecular weight polymer and is produced using a Ziegler catalyst, but it is expected that it will be difficult to satisfy the above-mentioned required characteristics with such a composition. In addition, examples of Patent Document 2 and Examples of Patent Document 3 disclose a fuel tank using an ethylene-based polymer produced with a titanium-based catalyst, which is excellent in impact resistance even with a thin wall thickness. There is. Further, in Patent Document 4 and Patent Document 5, a multimodal polyethylene molding material, which is also manufactured with a titanium-based catalyst and has improved ESCR-rigidity balance and swelling ratio, and a fuel manufactured from the hollow molding material. Hollow molding materials such as tanks are described.

  However, hollow bodies made of these ethylene-based polymers have excellent impact strength, but are insufficient to satisfy the requirements for further weight reduction, and are resistant to thermal deformation under stress over a long period of time, as typified by high temperature tensile creep. May not be fully expressed.

  Patent Document 6 proposes a multimodal polyethylene in which at least a high-molecular weight block is prepared with a metallocene catalyst, the tensile creep strain at 80 ° C. is 2.4% or less, and the Charpy impact at −40 ° C. is 15 KJ / m 2 or more. There is.

  Further, an ethylene-based polymer having excellent fluidity and moldability and excellent properties such as mechanical strength (Patent Documents 7 and 8), and an ethylene-based polymer that can be preferably used in a fuel tank (Patent Document 9) Is proposed.

  However, the hollow bodies made of these ethylene-based polymers have excellent impact strength, but since the high-molecular weight block is polymerized using a metallocene catalyst having a narrow molecular weight distribution, the high-molecular weight component is less than that of the existing titanium-based catalyst ((z +1) Since the average molecular weight is small) and the extensional flow characteristics are inferior, destabilization occurs on the surface of the molten resin in the high-speed flow field at the exit of the die, and there is a drawback that roughening tends to occur during molding.

  On the other hand, Patent Document 10 has a substantially narrow molecular weight distribution and a high Z-average molecular weight due to two or more highly active metallocene catalysts exhibiting different polymerization behaviors, and a high molecular weight component and a low molecular weight component are homogeneous. An ethylene-based polymer having a characteristic of a compatible molecular structure is described.

  However, these ethylene-based polymers have a narrow molecular weight distribution (Mw / Mn) for carrying out blow molding, have high shear stress on the wall surface in the die, and have the drawback that rough skin easily occurs.

Patent Document 11 uses a polymerization catalyst containing at least one transition metal compound containing a salicylaldimine ligand and at least one transition metal compound containing a cyclopentadienyl ligand to control the length and the amount of long-chain branching introduced. By doing so, an ethylene-based polymer having an excellent melt tension is described even in the single-stage polymerization method.
However, hollow bodies made of these ethylene-based polymers have a drawback that impact resistance and long-term fatigue properties are deteriorated by the introduction of long chain branching.

JP-A-6-172594 JP-A-7-090021 JP-A-7-101433 JP, 2003-510429, A Japanese Patent Publication No. 2006-193671 Japanese Patent Publication No. 2005-523968 WO2004 / 083265 pamphlet WO2006 / 019147 pamphlet WO2008 / 087945 pamphlet JP-A-2005-206777 JP, 2005-2333, A

  The inventors of the present invention have solved the above-mentioned various problems by using a specific catalyst for olefin polymerization, that is, have higher impact resistance, long-term fatigue characteristics and creep resistance characteristics than hollow molded articles made of conventional polyolefin resin materials. It has been found that an ethylene-based polymer is suitable for obtaining a hollow molded article that achieves the above-mentioned properties and overcomes the drawbacks of the conventional hollow molded articles that are excellent in product appearance and moldability.

That is, the ethylene polymer (α) of the present invention is characterized by simultaneously satisfying the following requirements [a], [b], [c], [d] and [e].
The ethylene-based polymer (α) of the present invention is a single ethylene-based polymer as long as it simultaneously satisfies the following requirements [a], [b], [c], [d] and [e], A mixture obtained by kneading and blending two or more kinds of ethylene-based polymers or known additives described below in an amount such that all the additives are usually 1% by weight or less in the ethylene-based polymer. Good.

  Further, the values ([a] to [h]) of various parameters defined by the claims of the present application for specifying the ethylene polymer (α) of the present invention are, after blending, as in Examples described later. It is a measured value of granulated pellets as a test object.

[a] The melt flow rate (HLMI) at a temperature of 190 ° C. and a load of 21.6 kg is in the range of 1.0 to 10 g / 10 minutes.
[b] The density is in the range of 945 to 965 kg / m ³ .

[c] length 5.0 mm, using a die having a diameter 0.5 mm, shear rate 19460s at 210 ° C. ^- pressure at ^{1 (σ,} Pa) and the relationship between the HLMI in the range of below.
log (σ) ≧ −0.12 × log (HLMI) +7.65
[d] The relationship between Charpy impact strength ( kJ / m ² ) at −40 ° C. measured according to JIS K7111 and HLMI is within the following range.
log (Charpy impact strength ) ≥ -1.1 x log (HLMI) + 2.16
[e] The swell ratio measured at 230 ° C is in the range of 1.56 or more.

  The ethylene polymer (α) of the present invention preferably satisfies the following requirement [f] in addition to the above requirements [a] to [e].

[f] The 50% crack initiation time (F ₅₀ ) in the environmental stress crack resistance test (ESCR test; test temperature 65 ° C., test piece thickness 3 mmt) measured according to ASTM D1693 is 300 hours or more.

The ethylene polymer (α) of the present invention more preferably satisfies the following requirement [g] in addition to the above requirements [a] to [f].
[g] In a tensile creep test (test temperature 80 ° C.) measured in accordance with JIS K7115, when the test stress is 6 MPa, the creep strain after 100 hours has passed is 15% or less.

A particularly preferred embodiment of the ethylene polymer (α) of the present invention satisfies the following requirement [h] in addition to the above requirements [a] to [g].
[h] Mw / Mn and Mz ₊₁ / Mw determined by gel permeation chromatography (GPC) measurement are in the following ranges.
4.0 ≦ (Mw / Mn) ≦ 22.0 and (Mz ₊₁ /Mw)≧16.0
The present invention relates to a hollow molded article containing a layer composed of the above ethylene polymer (α).
The present invention relates to a fuel tank, a kerosene can, a drum, a container for chemicals, a container for agricultural chemicals, a container for solvent, or a bottle, which is composed of the above hollow molded article.

  That is, the fuel tank and the agricultural chemical container of the present invention are composed of the layer (I) comprising the ethylene resin composition for hollow molding, the adhesive layer (IV), the barrier layer (II) and the regeneration layer (III). It is characterized in that it is composed of a hollow molded body including a laminated structure.

In addition, in the fuel tank and the agricultural chemical container of the present invention, the layer (I) made of the ethylene resin composition for hollow molding and the barrier layer (II) are laminated via the adhesive layer (IV). Is preferred. It is also preferable that the reproduction layer (III) and the barrier layer (II) are laminated via an adhesive layer.
In the fuel tank and the agricultural chemical container, the barrier layer (II) is preferably a layer containing an ethylene-vinyl alcohol copolymer.

  According to the present invention, it is possible to produce a hollow molded article and a multi-layer hollow molded article made of an ethylene polymer (α) which are particularly excellent in appearance, moldability and mechanical strength.

Hereinafter, the ethylene polymer (α) of the present invention will be specifically described.
<Ethylene polymer (α)>
The ethylene-based polymer (α) of the present invention is an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms, preferably ethylene and an α-olefin having 6 to 10 carbon atoms. is there. When an α-olefin having 4 carbon atoms is used as the α-olefin, it is preferable to also use an α-olefin having 6 to 10 carbon atoms. Examples of the α-olefin having 4 to 10 carbon atoms used for copolymerization with ethylene include 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene and 1-decene.

  If the α-olefin has 5 or less carbon atoms, the probability that the α-olefin will be incorporated into the crystal increases (see Polymer, vol. 31, p. 1999, 1990), and as a result, the resulting hollow molded article Strength tends to be weak. In addition, when the carbon number of the α-olefin exceeds 10, side chains (branches resulting from the α-olefin copolymerized with ethylene) may be crystallized, and the resulting hollow molded product is amorphous. The department tends to weaken.

The structural unit derived from the α-olefin is usually contained in an amount of 2.0 mol% or less, preferably 1.5 mol% or less, more preferably 1.30 mol% or less in all the structural units.
As will be described later, when the ethylene-based polymer is continuously polymerized in two or more stages, for example, only ethylene is homopolymerized in the first stage, and ethylene and α-olefin are copolymerized in the second stage. Good. In this case, the "all constitutional units" mean all constitutional units of the polymer finally obtained by continuously polymerizing in two or more stages.

  The ethylene polymer (α) of the present invention may be monomodal (multimodal) or may be multimodal (low molecular weight polymer and high molecular weight polymer, as will be described later). It is preferable that the compound has a multimodal property because it can easily control various parameter ranges defined in the present invention.

The ethylene polymer (α) of the present invention is characterized by simultaneously satisfying the following requirements [a] to [d].
The ethylene-based polymer (α) of the present invention is a mixture of two or more ethylene-based polymers even if it is a single ethylene-based polymer, as long as the following requirements [a] to [d] are simultaneously satisfied: Alternatively, it may be a composition.

  [a] Melt flow rate (HLMI) at a temperature of 190 ° C. and a load of 21.6 kg is 1.0 to 10 g / 10 minutes, preferably 1.5 to 7.0 g / 10 minutes, and more preferably 1.5 to It is in the range of 3.7 g / 10 minutes.

  If the HLMI is less than 1.0 g / 10 min, the load on the extruder during extrusion molding of the parison will be large, and the extrusion amount may not be secured enough to reduce the productivity. If it exceeds / 10 minutes, melt parison formation may become unstable due to insufficient melt viscosity or melt tension, and the resulting hollow molded article may have poor impact strength, which is not preferable.

  It is known that HLMI mainly depends on the molecular weight of the ethylene polymer, and the molecular weight of the ethylene polymer is determined by the composition ratio of hydrogen and ethylene (hydrogen / ethylene) in the polymerization system ( For example, Kazuo Soga et al., “Catalytic Olefin Polymerization”, Kodansha Scientific, 1990, p.376). Therefore, it is possible to increase / decrease the HLMI of the ethylene-based polymer by increasing / decreasing the amount of hydrogen / ethylene.

[b] The density is in the range of 945 to 965 kg / m ³ , preferably 948 to 960 kg / m ³ , and more preferably 949 to 959 kg / m ³ .
An ethylene-based polymer having a density of less than 945 kg / m ³ is not preferable because the hollow molded body obtained has insufficient rigidity or when used as a fuel tank, the rigidity tends to decrease due to swelling, while 965 kg / m 3 ^An ethylene-based polymer exceeding ³ is not preferable because the resulting hollow molded article becomes brittle and impact resistance and long-term fatigue characteristics such as ESCR characteristics are not exhibited.

  The density mainly depends on the α-olefin content of the ethylene-based polymer. The lower the α-olefin content, the higher the density, and the higher the α-olefin content, the lower the density. Further, it is known that the α-olefin content in an ethylene polymer is determined by the composition ratio of α-olefin and ethylene (α-olefin / ethylene) in the polymerization system (for example, Walter Kaminsky, Makromol. Chem. 193, p.606 (1992)). Therefore, by increasing / decreasing the α-olefin / ethylene, the ethylene polymer (α) having a density within the above range can be produced.

[c] length 5.0 mm, using a die having a diameter 0.5 mm, shear rate apparent at 210 ℃ 19460s ^- pressure at ^{1 (σ,} Pa) and the relationship between the HLMI is the following inequality (Eq-1 ) Is satisfied. The following inequality (Eq-1-2) is preferably satisfied, and particularly preferably the following inequality (Eq-1-2) is satisfied.
log (σ) ≧ −0.12 × log (HLMI) +7.65 (Eq−1)
log (σ) ≧ −0.12 × log (HLMI) +7.66 (Eq-1-2)
log (σ) ≧ −0.12 × log (HLMI) +7.68 (Eq-1-3)

  In the high-speed flow field at the exit of the die, the unstable phenomenon of rough skin such as sharkskin that occurs on the surface of molten resin such as ethylene polymer is related to the extension flow characteristics in the high-speed large deformation field, and the deformation amount is large. It is known that the sharkskin is less likely to occur in a system that can retain the elongation stress even in the region. (For example, T.I.Burghelea et al, /J.Non-Newtonian Fluid Mech.165 (2010) 1093-1104).

The following methods are known as methods for evaluating the extensional flow characteristics in a high-speed large deformation field.
In the capillary rheometer, an extensional flow occurs in the flow direction due to the contraction flow generated when the molten resin flows from the barrel into the die, but in the high-speed large deformation field, the resistance to this extensional flow, that is, the pressure loss based on the extensional viscosity, It is known that it becomes dominant and becomes sufficiently large compared to the pressure loss caused by shear flow (for example, Cogswell, FN Polym. Eng. Sci. 1972, 12, 64). Therefore, by reducing the pipe diameter of the die, a high-speed large deformation field can be generated at the inflow part to the die, and the land of the die can be shortened to reduce the shear pressure loss. It is possible to evaluate the extensional flow characteristics in a high-speed large deformation field by measuring.

It is generally known that introduction of long chain branching and / or introduction of a high molecular weight component into an ethylene-based polymer is effective for improving elongation flow characteristics. It is known that a monomodal ethylene polymer prepared by a metallocene catalyst has a narrow molecular weight distribution, and has a higher molecular weight component (ie, M _{Z +} ) than a monomodal ethylene polymer prepared by a Ziegler-Natta catalyst. ₁ ) The average molecular weight is small), and it is expected that the elongation flow characteristics will be poor.

By adjusting a bimodal polyethylene-based resin composition using a metallocene catalyst as described in WO 2008/087945, it is possible to adjust polyethylene having excellent fluidity and impact strength. However, since the high molecular weight component of the bimodal polyethylene resin composition using the metallocene catalyst is less than that of the bimodal polyethylene prepared by the Ziegler-Natta catalyst (that is, the M _{Z + 1} average molecular weight is small), the extension flow characteristics are improved. It tends to be inferior, and sharkskin tends to occur in the high-speed flow field at the die exit during blow molding. It is possible to improve the extensional flow characteristics by further increasing the molecular weight of the high molecular weight polymer by using a metallocene catalyst, but there is a poor appearance due to poor dispersion of the low molecular weight polymer component and the high molecular weight polymer component during blow molding. It tends to occur, and the shape and fusion strength of the pinch-off portion of the parison joint portion (fusion portion in which the parison is sandwiched between molds) are inferior. Also, by adjusting the multimodal polyethylene of more than trimodal using a metallocene catalyst, it becomes possible to introduce a high molecular weight polymer having a higher molecular weight than the high molecular weight polymer obtained from bimodal polyethylene. Although polyethylene having a high molecular weight component having a high molecular weight (that is, a component having a large M _{Z + 1} average molecular weight) can be obtained, it is preferable from the viewpoints of increased capital investment due to an increase in polymerization equipment and dispersibility of a higher molecular weight high molecular weight polymer. Absent.

Further, the extensional flow characteristics can be improved by introducing long-chain branching, but it is not preferable because impact resistance and long-term fatigue characteristics are likely to deteriorate.
In the ethylene polymer (α) of the present invention, a catalyst for olefin polymerization comprising a Group 4 transition metal compound capable of producing a high molecular weight polymer (hereinafter, may be referred to as “A-1” in the description). ) And a catalyst for olefin polymerization comprising a Group 4 transition metal compound capable of producing a further high molecular weight polymer (hereinafter, sometimes referred to as “A-2” in the description), at least two types By adjusting a bimodal (two-stage polymerization) ethylene-based polymer in the presence of an olefin polymerization catalyst consisting of a Group 4 transition metal compound, it is possible to maintain elongation stress even in the region where the amount of deformation during melting is large. It is possible to obtain an ethylene polymer (α) with excellent elongation flow characteristics, and it is possible to suppress sharkskin generated on the surface of the parison in the high-speed flow field at the die exit during hollow molding. You.

[d] The relationship between Charpy impact strength ( kJ / m ² ) at −40 ° C. measured according to JIS K7111 and HLMI satisfies the following inequality (Eq-2). The following inequality (Eq-2-2) is preferable, more preferably the following inequality (Eq-2-3) and the following inequality (Eq-2-4) are simultaneously expressed, and particularly preferably the following inequality (Eq-2-4) is used. The following inequality (Eq-2-5) is satisfied at the same time.
log (Charpy impact strength ) ≥ -1.1 x log (HLMI) + 2.16 ... (Eq-2)
log (Charpy impact strength ) ≥ -1.1 x log (HLMI) + 2.19 ... (Eq-2-2)
log (Charpy impact strength ) ≧ −1.1 × log (HLMI) +2.20 ... (Eq-2-3)
log (Charpy impact strength ) ≧ 1.6 (Eq-2-4)
log (Charpy impact strength ) ≧ -1.1 × log (HLMI) +2.25 ... (Eq-2-5)

  When the Charpy impact strength is within this range, the obtained hollow molded article can sufficiently withstand impact and drop impact to the hollow molded article caused by vibration, drop, vehicle accident and the like. In addition, increasing the container wall thickness to improve impact resistance impairs economic efficiency. The Charpy impact strength can be adjusted by the density of the ethylene polymer and HLMI, and the Charpy impact strength can be increased by decreasing the density or decreasing the HLMI.

[e] The swell ratio measured at 230 ° C. is 1.56 or more.
The swell ratio of the ethylene polymer (α) of the present invention is 1.56 or more, preferably 1.60 or more. Swell is a phenomenon in which the resin melt extruded from the die becomes larger in size than the slit width and clearance at the die outlet.If the swell ratio is small, it is difficult to control molding such as parison during blow molding. It is not preferable because of poor performance, and a large swell ratio is required to adjust the product thickness. The swell is an intrinsic viscosity of a high molecular weight polymer of an ethylene polymer polymerized from an olefin polymerization catalyst composed of a Group 4 transition metal compound (A-2) capable of producing a further high molecular weight polymer [ The swell can be increased by increasing [η].

  The ethylene-based polymer (α) of the present invention preferably satisfies the following requirements [f] or [g] at the same time in addition to the requirements [a] to [e]. Further, it is more preferable that the requirements [f] and [g] are simultaneously satisfied.

[f] In the environmental stress crack resistance test (ESCR test; test temperature 65 ° C., test piece thickness 3 mmt) measured according to ASTM D1693, 50% crack initiation time (F ₅₀ ) is 300 hours or more, preferably 400 It is at least hours, more preferably at least 500 hours. If the F ₅₀ is less than 300 hours, the resistance to environmental stress cracking is inferior, the container may break due to environmental stress cracking, and the internal solution may leak. The F ₅₀ of the ESCR test can be adjusted by the molecular weight, density and blending amount of the high molecular weight polymer of the ethylene-based polymer, and if the molecular weight of the high molecular weight polymer is increased, the density is decreased or the ratio is increased, the above F ₅₀ can be improved.

  [g] In a tensile creep test (test temperature 80 ° C.) measured according to JIS K7115, when the test stress is 6 MPa, the creep strain after 100 hours has passed is 15% or less, preferably 10% or less, more preferably Is 9.5% or less, particularly preferably 9.0% or less.

When the creep strain is in the above range, the creep deformability is particularly excellent at high temperatures, that is, the heat deformability is superior to conventional materials in the high temperature range expected when the hollow molded body is actually used in a fuel tank or the like. Therefore, it is possible to reduce the thickness of the hollow molded body. The creep strain can be adjusted by the density of the ethylene-based polymer and HLMI, and the creep strain can be reduced by increasing the density or decreasing the HLMI.
The ethylene polymer (α) of the present invention preferably satisfies the following requirement [h] in addition to the above requirements [a] to [g].

[h] The relationship between Mw / Mn and Mz ₊₁ / Mw determined by gel permeation chromatography (GPC) measurement is represented by the following inequality (Eq-3-1) and inequality (Eq-3-2). Meet at the same time. The following inequality (Eq-3-2) and the following inequality (Eq-3-3) are preferably satisfied at the same time, and particularly preferably, the following inequality (Eq-3-4) and the following inequality (Eq-3-5) are satisfied at the same time.
4.0 ≦ (Mw / Mn) ≦ 22.0 ... (Eq-3-1)
(Mz _{+ 1 /} Mw) ≧ 16.0 (Eq-3-2)
6.0 ≦ (Mw / Mn) ≦ 21.0 ... (Eq-3-3)
8.0 ≦ (Mw / Mn) ≦ 20.0 ... (Eq-3-4)
(Mz _{+ 1 /} Mw) ≧ 17.0 ... (Eq-3-5)

An ethylene polymer having an Mw / Mn of less than 4.0 is not preferable because the extrusion load at the time of molding process becomes too high, causing a problem in processability and destabilizing the parison during blow molding.
An ethylene-based polymer having an Mw / Mn of more than 22.0 is likely to have a poor appearance during blow molding due to poor dispersion of a low molecular weight polymer and a high molecular weight polymer, and has an intrinsic viscosity [η] of 5.0 or less. In the ethylene polymer, the low molecular weight component is excessively increased, so that the resulting hollow molded article does not exhibit impact resistance, which is not preferable. Further, the shape and fusion strength of the pinch-off portion (fusion portion between the parison sandwiched between the molds) of the parison joint portion becomes inferior, and the drop strength may decrease, which is not preferable.

Mz _{+ 1} / Mw represents the molecular weight distribution of the high molecular weight component, and represents the molecular weight distribution of the component having a higher molecular weight than Mz / Mw. The fact that Mz ₊₁ / Mw is large relative to Mw / Mn means that the molecular weight distribution of the high molecular weight component is wide, a very high molecular weight component is present, and the component ratio is high.

The ethylene-based polymer having a Mz ₊₁ / Mw of more than 16.0 has excellent elongation flow characteristics due to the component having a very high molecular weight contained in the ethylene-based polymer, and as a result, the molten resin is not melted in the high-speed flow field at the die exit. Since it is stable, it is possible to prevent rough skin during molding at the die exit.

The upper limit of Mz ₊₁ / Mw of the ethylene polymer (α) of the present invention is not particularly limited, but Mz ₊₁ / Mw is preferably 70.0 or less, particularly preferably 50.0 or less. If Mz ₊₁ / Mw is too large, a component having a very high molecular weight may be apt to cause poor dispersion, and shearing stress on the wall surface inside the die may be high, causing rough skin inside the die.

  In addition to satisfying the requirements [a] to [g], the ethylene polymer (α) of the present invention has an intrinsic viscosity [η] of 2.5 to 6.0 (dl / g), preferably 3. It is a particularly preferred embodiment that the content of 0 to 5.0 (dl / g) is also satisfied. The ethylene polymer having an intrinsic viscosity within this range exhibits excellent properties in fluidity, rigidity and low temperature impact resistance.

<Method for producing ethylene polymer (α)>
The ethylene polymer (α) of the present invention is an olefin polymerization catalyst, for example,
(A-1) a transition metal compound of Group 4 of the periodic table represented by the following general formula [I] (may be referred to as “A-1” in the following description),
(A-2) A transition metal compound of Group 4 of the periodic table represented by the following general formula [III] (may be referred to as “A-2” in the following description) and (B) (B-1) organic compound. Metal compounds,
(B-2) an organoaluminum oxy compound, and
(B-3) At least one compound selected from compounds that form an ion pair by reacting with a transition metal compound (hereinafter sometimes referred to as “cocatalyst”) and optionally used (C ) It can be suitably produced by homopolymerizing ethylene using an olefin polymerization catalyst formed from a carrier or by copolymerizing ethylene with the above-mentioned α-olefin having 6 to 10 carbon atoms. it can.

Hereinafter, each component (A-1), (A-2), (B) and (C) will be described in detail.
(A-1) Transition Metal Compound The transition metal compound (A-1) is a compound represented by the general formula [I] described below.

上記一般式[I]において、R⁷、R⁸、R⁹、R¹⁰、R¹¹、R¹²、R¹³、R¹⁴、R¹⁵、R¹⁶、R¹⁷、R¹⁸、R¹⁹およびR²⁰は、それぞれ水素原子、炭化水素基、であり、それぞれ同一でも異なっていてもよく、R⁷〜R¹⁸までの隣接した置換基は互いに結合して環を形成してもよく、R¹⁹およびR²⁰は不飽和結合および/または芳香族環を含んでいてもよい炭素原子数2〜20の2価の炭化水素基であり、Mは周期律表第4族から選ばれた金属であり、Qはハロゲン原子、炭化水素基、アニオン配位子または孤立電子対で配位可能な中性配位子から同一または異なる組合せで選ばれ、jは1〜4の整数である。

In the above general formula [I], R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ and R ²⁰ are , Each is a hydrogen atom, a hydrocarbon group, and may be the same or different, and adjacent substituents R ^{7 to} R ¹⁸ may combine with each other to form a ring, and R ¹⁹ and R ²⁰ Is a divalent hydrocarbon group having 2 to 20 carbon atoms which may contain an unsaturated bond and / or an aromatic ring, M is a metal selected from Group 4 of the periodic table, and Q is A halogen atom, a hydrocarbon group, an anion ligand, or a neutral ligand capable of coordinating with a lone electron pair is selected in the same or different combination, and j is an integer of 1 to 4.

Among the transition metal compounds (A-1) represented by the above general formula [I], the compounds preferably used are those in which R ^{7 to} R ¹⁰ are hydrogen atoms, Y is a carbon atom, and M is zirconium. A compound in which j is 2 and is an atom.

Further, in the transition metal compound (A-1) represented by the above general formula [I], the bridging atom Y of the covalent bond bridging portion has aryl groups which may be the same or different from each other. (That is, R ¹⁹ and R ²⁰ are aryl groups which may be the same or different from each other). Examples of the aryl group include a phenyl group, a naphthyl group, an anthracenyl group, and a group in which one or more of these aromatic hydrogens (sp2-type hydrogens) are substituted with a substituent. Examples of the substituent include a hydrocarbon group (f1) having 1 to 20 total carbon atoms. Examples of such a group (f1) include a methyl group, an ethyl group, an n-propyl group, an allyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group. Group, n-nonyl group, n-decanyl group and other linear hydrocarbon groups; isopropyl group, tert-butyl group, amyl group, 3-methylpentyl group, 1,1-diethylpropyl group, 1,1-dimethyl Branched groups such as butyl group, 1-methyl-1-propylbutyl group, 1,1-propylbutyl group, 1,1-dimethyl-2-methylpropyl group, 1-methyl-1-isopropyl-2-methylpropyl group Hydrocarbon group; Cyclic saturated hydrocarbon group such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, norbornyl group, adamantyl group; Cyclic unsaturated such as phenyl group, naphthyl group, biphenyl group, phenanthryl group, anthracenyl group Hydrocarbon groups and this Alkyl substituted products of benzyl, saturated hydrocarbon groups substituted with aryl groups such as benzyl, cumyl, etc .; methoxy, ethoxy, phenoxy, N-methylamino, trifluoromethyl, tribromomethyl, pentafluoro Hetero atom-containing hydrocarbon groups such as an ethyl group and a pentafluorophenyl group can be mentioned.

  In the present invention, the hydrocarbon group (f1) is preferably a cyclic saturated hydrocarbon group or a nuclear alkyl substitution product, and a more preferable specific example is a metallocene compound represented by the compound [II]. .

なお、上記式[II]で表わされる遷移金属化合物は、270MHz ¹H-NMR（日本電子 GSH-270）およびFD-質量分析（日本電子SX-102A）などを用いて同定することができる。

The transition metal compound represented by the above formula [II] can be identified using 270 MHz ¹ H-NMR (JEOL GSH-270) and FD-mass spectrometry (JEOL SX-102A).

(A-2) Transition metal compound The transition metal compound (A-2) is a compound represented by the following general formula [III].
The polyethylene polymer (α) of the present invention can be produced by using the following transition metal compound [III] together with the transition metal compound represented by the above formula [I]. Particularly, it is preferably used together with the transition metal compound of the transition metal compound [II].

  The transition metal compound of the component (A-2) used in the present invention is a transition metal compound of Group 4 of the periodic table represented by the following general formula [III]. The transition metal compound of Group 4 of the periodic table represented by the following general formula [III] will be described in detail.

〔一般式［III］中、Ｍは周期律表第４族遷移金属原子を示し、ｍは、１〜４の整数を示し、Ｒ¹〜Ｒ⁵は、水素原子、炭化水素基、ケイ素含有基を示し、互いに同一でも異なっていてもよく、これらのうちの２個以上が互いに連結して環を形成していてもよく、ｍが２以上の場合にはＲ¹〜Ｒ⁵で示される基のうち少なくとも２個の基が連結されていてもよく、Ｒ⁶は、下記一般式［IV］で表される基であり、ｊは、Ｍの価数を満たす数であり、Ｘは、水素原子、ハロゲン原子、炭化水素基、酸素含有基、イオウ含有基、窒素含有基、ホウ素含有基、アルミニウム含有基、リン含有基、ハロゲン含有基、ヘテロ環基、ケイ素含有基、ゲルマニウム含有基、またはスズ含有基を示し、ｊが２以上の場合は、Ｘで示される複数の基は互いに同一でも異なっていてもよく、またＸで示される複数の基は互いに結合して環を形成してもよい。〕

[In the general formula [III], M represents a Group 4 transition metal atom of the periodic table, m represents an integer of 1 to 4, and R ^{1 to} R ⁵ represent a hydrogen atom, a hydrocarbon group, or a silicon-containing group. And may be the same or different from each other, two or more of them may be linked to each other to form a ring, and when m is 2 or more, the groups represented by R ^{1 to} R ⁵ are represented. At least two groups may be linked together, R ⁶ is a group represented by the following general formula [IV], j is a number satisfying the valence of M, and X is hydrogen. Atom, halogen atom, hydrocarbon group, oxygen-containing group, sulfur-containing group, nitrogen-containing group, boron-containing group, aluminum-containing group, phosphorus-containing group, halogen-containing group, heterocyclic group, silicon-containing group, germanium-containing group, or A tin-containing group, and when j is 2 or more, a plurality of groups represented by X may be the same as each other. May have become, the a plurality of groups may be bonded to each other to form a ring represented by X. ]

In the above general formula [III], N ... M generally indicates coordination, but in the present invention, it may or may not coordinate.
In the general formula [I], M is specifically titanium, zirconium or hafnium, preferably zirconium.
m is preferably 2.

  In the general formula [III], X represents a hydrogen atom, a halogen atom, a hydrocarbon group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group, a boron-containing group, an aluminum-containing group, a phosphorus-containing group, a halogen-containing group, a heterocycle. A group, a silicon-containing group, a germanium-containing group, or a tin-containing group is shown, and among them, a hydrogen atom, a halogen atom, a hydrocarbon group, and a silicon-containing group are preferable.

Examples of the halogen atom include fluorine, chlorine, bromine and iodine, and chlorine is most preferably used.
In the general formula [III], examples of ^{R 1 ~R 5, R 1 ~R} 5 represent a hydrogen atom, a hydrocarbon group, and may be the same or different from each other, connecting two or more of these with each other And may form a ring, and when m is 2 or more, at least two groups out of the groups represented by R ^{1 to} R ⁵ may be linked. R ^{1 to} R ⁵ may be the same as or different from each other, and at least two groups out of the groups represented by R ^{1 to} R ⁵ may be linked. Of these, a hydrogen atom and a hydrocarbon group are particularly preferable.

Specific examples of the hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a neopentyl group, an n-hexyl group and an adamantyl group. A linear or branched, or cyclic alkyl group having 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms, such as a phenyl group, a naphthyl group, a biphenyl group, a terphenyl group, a phenanthryl group, or an anthracenyl group. An aryl group having 6 to 30 carbon atoms, preferably 6 to 20 carbon atoms may be substituted. Among them, R ² or R ³ is a methyl group, an ethyl group or an optionally substituted phenyl group, and R ⁵ is a t-butyl group, an adamantyl group, a dimethylphenyl group or a methyldiphenyl group. Is preferable from the viewpoint that the polymer of the invention can be obtained.

In the general formula [III], R ⁶ is a group represented by [IV] (where a black circle () represents the point of attachment to the nitrogen atom).

一般式［ＩＶ］中、Ｒ¹³は、炭素数３以上８以下の二価の飽和炭化水素基であり、例えば、トリメチレン、テトラメチレン、ペンタメチレン、ヘキサメチレンなどが挙げられ、好ましくは炭素数４以上６以下の二価の飽和炭化水素基（例えば、テトラメチレン、ペンタメチレン、ヘキサメチレン）であり、特に好ましくは炭素数４の二価の飽和炭化水素基（例えば、テトラメチレン）である。

In the general formula [IV], R ¹³ is a divalent saturated hydrocarbon group having 3 or more and 8 or less carbon atoms, and examples thereof include trimethylene, tetramethylene, pentamethylene and hexamethylene, and preferably 4 carbon atoms. It is a divalent saturated hydrocarbon group having 6 or more and 6 or less (eg, tetramethylene, pentamethylene, hexamethylene), and particularly preferably a divalent saturated hydrocarbon group having 4 carbon atoms (eg, tetramethylene).

In the general formula [IV], R ¹² and R ¹⁴ represent a halogen atom or a C1 to C20 hydrocarbon group and may be branched or cyclic, and may be the same or different from each other. Examples of the hydrocarbon include the same groups as those exemplified for R ^{1 to} R ⁵ , and although they are aliphatic or aromatic, which can be mentioned as an example thereof, a polymer characteristic of the present application is obtained. Therefore, it is preferable to use an aliphatic hydrocarbon. R ¹² is preferably located at the α-position of the carbon to which the formula [IV] is bonded to the nitrogen, from the viewpoint of obtaining the ethylene polymer of the present application.

  Among these, particularly, the number of carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, neopentyl group, n-hexyl group. 1 to 30, preferably 1 to 20 linear or branched alkyl group; phenyl group, naphthyl group, biphenyl group, terphenyl group, phenanthryl group, anthracenyl group and the like having 6 to 30 carbon atoms, preferably 6 An aryl group having from 20 to 20; a halogen atom, an alkyl group having 1 to 30 carbon atoms, preferably an alkyl group having 1 to 20 carbon atoms or an alkoxy group, an aryl group having 6 to 30 carbon atoms, preferably an aryloxy group having 6 to 20 carbon atoms. Substituted aryl groups having 1 to 5 substituents such as groups are preferred.

n is 0 or an integer not more than twice the number of carbon atoms of R ¹³ , and when n is an integer not less than 2, a plurality of R ¹⁴ may be the same or different from each other.
In the general formula [IV], a black circle (●) represents a bonding point with the nitrogen atom.
In general formula [III], j is a number that satisfies the valence of M, and is specifically an integer of 0 to 5, preferably 1 to 4, and more preferably 1 to 3.

In the general formula [III], X represents a hydrogen atom, a halogen atom, a hydrocarbon group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group, a boron-containing group, an aluminum-containing group, a phosphorus-containing group, a halogen-containing group, a heterocycle. A containing group, a silicon-containing group, a germanium-containing group, or a tin-containing group, and when j is 2 or more, the plurality of groups represented by X may be the same or different from each other, and the plurality of groups represented by X may be the same. The groups may combine with each other to form a ring.
From the above points, the most preferable compounds for obtaining the ethylene polymer of the present application are listed below.

前記第４族遷移金属化合物の具体的な例においてｔ−Ｂｕはｔｅｒｔ−ブチル基を表し、Ｐｈはフェニル基を表し、Ｍｅはメチル基を表し、Ａｄｍは１−アダマンチル基を示す。

In a specific example of the Group 4 transition metal compound, t-Bu represents a tert-butyl group, Ph represents a phenyl group, Me represents a methyl group, and Adm represents a 1-adamantyl group.

  In the present invention, in these compounds, a transition metal compound in which zirconium is replaced with a transition metal of Group 4 of the periodic table other than zirconium such as titanium and hafnium can also be used.

  The method for producing such a transition metal compound (A-2) is not particularly limited, and for example, it can be produced by the method described in JP-A-11-315109 or EP0874005A1 by the present applicant.

In the present invention, the transition metal compound (A-2) represented by the formula [III] is represented by R ⁶ in the formula [III] because a substituent is present in R ¹² in the formula [IV]. It is considered that the rotation of the substituent is suppressed, the reaction field in the vicinity of the transition metal is narrowed, and chain transfer to the monomer or Al is less likely to occur, so that the molecular weight is extended and a high molecular weight olefin polymer is obtained. On the other hand, if the reaction field is too narrow, the activity may decrease, so that the substituent of R ¹² in the formula [IV] is a hydrocarbon group, preferably a methyl group, an ethyl group, n -Propyl group, n-butyl group, and more preferably methyl group.
It should be noted that two or more different compounds can be used as the component of the general formula (IV).

(B) Cocatalyst [(B-1) Organometallic compound]
Specific examples of the (B-1) organometallic compound include organometallic compounds of Groups 1 and 2 and Groups 12 and 13 of the Periodic Table as shown below.

General formula R ^a _m Al (OR ^b ) _n H _p X _q
(In the formula, R ^a and R ^{b, which} may be the same or different from each other, represent a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4, X represents a halogen atom, and m represents 0. <M ≦ 3, n is 0 ≦ n <3, p is 0 ≦ p <3, q is a number 0 ≦ q <3, and m + n + p + q = 3). It is an organic aluminum compound.
The aluminum compound used in the examples described later is triisobutylaluminum or triethylaluminum.

[(B-2) Organoaluminum oxy compound]
The (B-2) organoaluminum oxy compound optionally used in the present invention may be a conventionally known aluminoxane, or a benzene-insoluble organoaluminum as exemplified in JP-A-2-78687. It may be an oxy compound.
The organoaluminum oxy compound used in the examples described below is a commercially available MAO (= methylalumoxane) / toluene solution manufactured by Nippon Alkyl Aluminum Co., Ltd.

[(B-3) Compound that reacts with a transition metal compound to form an ion pair]
The compound (B-3) used in the present invention which reacts with the transition metal compound (A-1) and the transition metal compound (A-2) to form an ion pair (hereinafter referred to as "ionized ionic compound"). As, JP 1-501950, JP 1-502036 JP, JP 3-179005 JP, JP 3-179006 JP, JP 3-207703 JP, JP 3-207704 JP US Pat. No. 5,321,106, Lewis acids, ionic compounds, borane compounds, carborane compounds and the like can be mentioned. Furthermore, heteropoly compounds and isopoly compounds can also be mentioned. Such ionized ionic compounds (B-3) may be used alone or in combination of two or more.
In addition, as the non-limiting component (B), the above-mentioned (B-1) and (B-2) are used in combination in Examples described later.

(C) Fine Particle Carrier The fine particle carrier (C) used as necessary in the present invention is an inorganic or organic compound, and is a granular or fine particle solid. Among them, the inorganic compound is preferably a porous oxide, an inorganic halide, clay, a clay mineral, or an ion-exchange layered compound. Such a porous oxide has different properties depending on the type and production method, but the carrier preferably used in the present invention has a particle size of 1 to 300 μm, preferably 3 to 200 μm, and a specific surface area of 50 to 1000. (m ² / g), preferably 100 to 800 (m ² / g), and the pore volume is preferably 0.3 to 3.0 (cm ³ / g). Such a carrier is used after firing at 80 to 1000 ° C., preferably 100 to 800 ° C., if necessary.

  The catalyst for olefin polymerization according to the present invention includes the above-mentioned transition metal compound (A-1) and transition metal compound (A-2), (B-1) organometallic compound, (B-2) organoaluminum oxy compound, And (B-3) at least one compound (B) selected from ionized ionic compounds, and a particulate carrier (C) used if necessary, together with a specific organic compound component as described below, if necessary. It may also include (D).

(D) Organic compound component In the present invention, the (D) organic compound component is used for the purpose of improving the polymerization performance and the physical properties of the produced polymer, if necessary. Examples of such organic compounds include alcohols, phenolic compounds, carboxylic acids, phosphorus compounds and sulfonates.

  The ethylene polymer according to the present invention is obtained by homopolymerizing ethylene as described above, or by copolymerizing ethylene with an α-olefin having 6 to 10 carbon atoms, using the above-mentioned olefin polymerization catalyst. Alternatively, the homopolymerization and the copolymerization may be carried out continuously in any order.

At the time of polymerization, the use method and addition order of each component are arbitrarily selected, and the following methods (P1) to (P10) are exemplified.
(P1) components (A-1) and (A-2) and at least one selected from (B-1) organometallic compounds, (B-2) organoaluminum oxy compounds and (B-3) ionized ionic compounds A method of adding a seed component (B) (hereinafter simply referred to as "component (B)") to the polymerization vessel in any order.

(P2) A method in which a catalyst in which the components (A-1) and (A-2) and the component (B) are contacted in advance is added to a polymerization vessel.
(P3) A method in which the catalyst components in which the components (A-1) and (A-2) and the component (B) are contacted in advance, and the component (B) are added in any order to the polymerization vessel. In this case, each component (B) may be the same or different.

(P4) A method of adding a catalyst component comprising components (A-1) and (A-2) supported on a particulate carrier (C), and component (B) to a polymerization vessel in any order.
(P5) A method of adding a catalyst component in which components (A-1) and (A-2) and component (B) are supported on a particulate carrier (C) to a polymerization vessel.

  (P6) A catalyst component comprising components (A-1) and (A-2) and component (B) supported on a particulate carrier (C), and a method of adding component (B) to a polymerization vessel in any order. . In this case, each component (B) may be the same or different.

(P7) A method of adding the catalyst component in which the component (B) is supported on the particulate carrier (C), and the components (A-1) and (A-2) to the polymerization vessel in any order.
(P8) A method in which the catalyst component in which the component (B) is supported on the particulate carrier (C), the components (A-1) and (A-2), and the component (B) are added to the polymerization vessel in any order. In this case, each component (B) may be the same or different.

  (P9) Components (A-1) and (A-2) and component (B) are supported on a particulate carrier (C), and a catalyst component obtained by contacting component (B) in advance is polymerized. How to add to the vessel. In this case, each component (B) may be the same or different.

  (P10) A catalyst component in which components (A-1) and (A-2) and component (B) are supported on a particulate carrier (C), and a catalyst component in which component (B) is contacted in advance, and a component A method of adding (B) to the polymerization vessel in any order. In this case, each component (B) may be the same or different.

In each of the above methods (P1) to (P10), at least two or more of the catalyst components may be contacted in advance.
A method of using a solid catalyst component in which the components (A-1) and (A-2) and the component (B) are supported on the fine particle carrier (C), that is, (P5), (P6), (P9) ) And (P10), the olefin may be prepolymerized. The prepolymerized solid catalyst component is usually constituted by prepolymerizing 0.1 to 1000 g, preferably 0.3 to 500 g, particularly preferably 1 to 200 g of polyolefin per 1 g of the solid catalyst component. Examples of the olefin used for the prepolymerization include ethylene and the above-mentioned α-olefins having 6 to 10 carbon atoms, and among these, ethylene is preferably used. In the present invention, the ethylene polymer is usually prepared by a method using the fine particle carrier (C), and preferably the components (A-1) and (A-2) and the component (B) are mixed with the fine particle carrier (C). The method of adding the catalyst component in which ethylene is prepolymerized to the catalyst component supported in (4) and the component (B) to the polymerization vessel in an arbitrary order is adopted.

Further, for the purpose of smoothly proceeding the polymerization, an antistatic agent, an antifouling agent or the like may be used in combination or may be supported on the carrier.
The polymerization can be carried out by either a liquid phase polymerization method such as solution polymerization or suspension polymerization or a gas phase polymerization method, but the suspension polymerization and the gas phase polymerization method are preferably adopted from the viewpoint of productivity.

  As the inert hydrocarbon medium used in the liquid phase polymerization method, specifically, aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; cyclopentane, cyclohexane, methyl Examples thereof include alicyclic hydrocarbons such as cyclopentane; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as ethylene chloride, chlorobenzene and dichloromethane, or a mixture thereof, and the olefin itself. It can also be used as a solvent. In the examples described below, the suspension polymerization method using hexane as an inert hydrocarbon medium was used as a non-limiting example.

When carrying out (co) polymerization using the above-mentioned olefin polymerization catalyst, the components (A-1) and (A-2) are usually ^{added in an amount of} 10 ^-12 to 10 ^-2 mol per liter of the reaction volume. It is preferably used in an amount so as to be 10 ⁻¹⁰ to 10 ⁻³ mol.

  The component (B-1) used as necessary is a molar ratio of the component (B-1) to the transition metal atom (M) in the components (A-1) and (A-2) [(B- 1) / M] is usually used in an amount of 0.01 to 100,000, preferably 0.05 to 50,000.

  The component (B-2) used as required is a molar ratio of the aluminum atom in the component (B-2) and the transition metal atom (M) in the components (A-1) and (A-2). [(B-2) / M] is usually used in an amount of 10 to 500,000, preferably 20 to 100,000.

  The component (B-3) used as necessary is a molar ratio of the component (B-3) to the transition metal atom (M) in the components (A-1) and (A-2) [(B- [3) / M] is usually used in an amount of 1 to 100, preferably 2 to 80.

  When the component (B) is the component (B-1), the molar ratio [(D) / (B-1)] of the component (D) used as necessary is usually 0.01 to 10, preferably 0.1. When the component (B) is the component (B-2), the molar ratio [(D) / (B-2)] is usually 0.001 to 2, preferably 0.005 to 1. When the component (B) is the component (B-3), the molar ratio [(D) / (B-3)] is usually 0.01 to 10, preferably 0.1 to 5. Used in quantity.

The polymerization temperature is usually in the range of -50 to + 250 ° C, preferably 0 to 200 ° C, particularly preferably 60 to 170 ° C. Polymerization pressure is usually atmospheric pressure to 100 (kg / cm ² ), preferably atmospheric pressure to 50 (kg / cm ² ) conditions, the polymerization reaction is batch (batch type), semi-continuous, continuous It can be done in either way of the formula. Polymerization is usually carried out in a gas phase or a slurry phase in which polymer particles are precipitated in a solvent. In the case of slurry polymerization or gas phase polymerization, the polymerization temperature is preferably 60 to 90 ° C, more preferably 65 to 85 ° C. By polymerizing in this temperature range, an ethylene polymer having a narrower composition distribution can be obtained.

  The ethylene polymer (α) of the present invention may have a monomodal or multimodal elution curve in gel permeation chromatography (GPC). However, a multimodal ethylene polymer is preferable from the viewpoint that it is easy to tune the numerical values of each requirement within the claims of the requirements [a] to [g] according to the present invention.

  The multi-modal ethylene-based polymer is prepared by separately producing two or more kinds of polymers in different polymerization vessels, and then satisfying the above requirements that the ethylene-based polymer (α) of the present invention should satisfy. It may be prepared by blending with, or it may be adjusted by carrying out the second stage polymerization after the first stage polymerization in the same polymerization vessel, or two or more stages arranged in series with different reaction conditions. It may be continuously prepared using a polymerization vessel.

  For example, when the ethylene polymer (α) of the present invention is prepared in two steps using the same polymerization vessel or in two steps using two or more series-arranged polymerization vessels having different reaction conditions, An ethylene homopolymer having an intrinsic viscosity of 0.6 to 2.0 (dl / g), preferably 0.9 to 1.9 (dl / g) in the first-stage polymerization vessel, is added to the total amount of 50 to 75% by weight. %, Preferably 55 to 70% by weight, and an ethylene copolymer having an intrinsic viscosity of 5.5 to 15 (dl / g), preferably 6.5 to 13 (dl / g) in the second-stage polymerization vessel. Is produced in an amount of 25 to 50% by weight, preferably 30 to 45% by weight. The order of producing the ethylene homopolymer and the ethylene copolymer may be reversed, but the ethylene homopolymer is preferably used because the ethylene resin composition for hollow molding of the present invention is easy to control the above requirements. The preliminarily manufactured formulation is preferably adopted.

  The intrinsic viscosity of the high molecular weight polymer of the ethylene copolymer polymerized in the second-stage polymerization vessel with the transition metal compound (A-2) is 10 to 40 (dl / g), preferably 10 to 30 (dl / g). g), particularly preferably 13 to 25 (dl / g), and the polymerization amount of the high molecular weight polymer of the ethylene copolymer polymerized by the transition metal compound (A-2) in the second-stage polymerization vessel is The total amount is 3 to 15% by weight, preferably 4 to 10% by weight.

  The intrinsic viscosity of the high molecular weight polymer of the ethylene copolymer polymerized in the second stage polymerization vessel with the transition metal compound (A-1) is 4 to 9.5 (dl / g), preferably 6 to 9. It is 5 (dl / g).

  The intrinsic viscosity and polymerization amount of the high molecular weight polymer of the ethylene copolymer polymerized in the second stage polymerization vessel of the transition metal compound (A-2), and the second stage depending on the transition metal compound (A-1) When the intrinsic viscosity of the high molecular weight polymer of the ethylene copolymer polymerized in the polymerization vessel is within the above range, the extensional flow characteristics are excellent, the swell is large, the occurrence of poor dispersion is suppressed, and the pinch-off part of the parison joint is good. Becomes

The polymerization amount ratio of the transition metal compound (A-1) and the transition metal compound (A-2) in the ethylene copolymer polymerized in the second-stage polymerization vessel is as follows. It is determined by the polymerization activity ratio of the second stage high molecular weight polymer. The polymerization amount of the second-stage high-molecular-weight polymer is such that the homopolymerization activity (second stage) of each transition metal compound is δ for the transition metal compound (A-1) and ε (for the transition metal compound (A-2). (Second stage): ((A-1) component second stage polymerization amount: wt%) = (second stage polymerization amount: wt%) _{(ethylene composition)} × δ / (δ + ε) ), And ((A-2) component second-stage polymerization amount: wt%) = (second-stage polymerization amount: wt%) _{(ethylene-based composition)} × ε / (δ + ε) I can do things. However, the homopolymerization activity of the second stage is the polymerization activity that has undergone the history of the first stage.

The intrinsic viscosity of the high molecular weight polymer of the ethylene copolymer polymerized in the second-stage polymerization vessel of the transition metal compound (A-1) and the transition metal compound (A-2) is such that each metallocene compound is polymerized alone. It is determined by the intrinsic viscosity of the second stage high molecular weight polymer. The intrinsic viscosity of the second step is [η] _{(ethylene composition)} = ([η] _{(first step composition)} x (first step polymerization amount: weight%) + [η] _{(second step Composition)} x (polymerization amount in second stage:% by weight)) / 100.

  In a preferred method of preparation using the particulate carrier (C), the polymer obtained is usually in the form of particles of about several tens to several thousands μmφ. When the polymerization is carried out in a continuous system having two or more polymerization vessels, it may be necessary to perform operations such as dissolving in a good solvent and then precipitating in a poor solvent, or sufficiently melting and kneading with a specific kneader.

  The molecular weight of the obtained ethylene-based polymer particles can be adjusted by allowing hydrogen molecules to exist in the polymerization system or changing the polymerization temperature. Further, it can be adjusted depending on the difference in the component (B) used.

The polymer particles obtained by the polymerization reaction are usually pelletized by the following method.
(1) A method of mechanically blending ethylene polymer particles and other components, which are optionally added, with an extruder, a kneader, etc., and cutting them into a predetermined size.

  (2) Dissolve the ethylene polymer particles and optionally other components added thereto in a suitable good solvent (for example, a hydrocarbon solvent such as hexane, heptane, decane, cyclohexane, benzene, toluene and xylene), and then dissolve the solvent. Is removed, and then mechanically blended using an extruder, a kneader or the like, and cut into a predetermined size.

  In addition, when the ethylene polymer (α) of the present invention is composed of two or more kinds of ethylene polymers, in the above (1) or (2), two or more kinds of ethylene polymers are used as the ethylene polymer. May be used as a mixture.

The ethylene polymer (α) of the present invention is particularly preferable for molding a hollow body described later.
The ethylene-based polymer (α) of the present invention includes a weather resistance stabilizer, a heat resistance stabilizer, an antistatic agent, an antislip agent, an antiblocking agent, an antifogging agent, a lubricant, within a range that does not impair the object of the present invention. Additives such as dyes, nucleating agents, plasticizers, antiaging agents, hydrochloric acid absorbents, antioxidants, etc., carbon black, titanium oxide, titanium yellow, phthalocyanine, isoindolinone, quinacridone compounds, condensed azo compounds, ultramarine blue, cobalt blue Pigments such as may be blended if necessary.

<Hollow molded body>
The hollow molded article of the present invention comprises the above-mentioned ethylene polymer (α) of the present invention, and preferred embodiments of the hollow molded article are a fuel tank, a drum, a pesticide container, an IBC, and a container.

  The hollow molded article of the present invention is a hollow molded article containing a layer composed of the ethylene polymer (α) of the present invention. That is, the hollow molded article of the present invention may be formed of a single layer such as a single-layer container, or may be formed of two or more layers such as a multi-layer container, and its wall thickness is It can be arbitrarily changed within the range of 100 μm to 5 mm depending on the application.

  For example, when the multi-layer container is formed of two layers, the first layer is formed of the above-mentioned ethylene polymer (α) of the present invention, and the other layer is formed of the first layer of the present invention. Is formed of a polymer different from the ethylene-based polymer (α), or is the ethylene-based polymer (α) of the present invention, which is the ethylene-based polymer (α) used in the first layer. It can also be formed from an ethylene polymer (α) having physical properties different from

  Examples of the above-mentioned "different polymer" include polyamide (nylon 6, nylon 66, nylon 12, copolymerized nylon, etc.), ethylene / vinyl alcohol copolymer, polyester (polyethylene terephthalate, etc.), modified polyolefin and the like. it can. Of these, ethylene / vinyl alcohol copolymers and polyamide resins having a gas barrier function that are not exhibited by polyethylene are preferably used. At that time, in order to increase the interlayer adhesive strength, a layer of a gas barrier resin such as ethylene / vinyl alcohol copolymer or polyamide resin is laminated and integrated with the above-mentioned polyethylene resin layer via the layer of the adhesive resin. The above arrangement is preferable, whereby a container having excellent impact resistance and gas barrier property can be manufactured. As the adhesive resin, an adhesive polyolefin resin is preferable, and for example, a carboxylic acid graft-modified polyolefin or a metal ion crosslinked product of an ethylene / unsaturated carboxylic acid copolymer can be used.

Preferred embodiments of the hollow molded article of the present invention are a fuel tank, a drum, and a pesticide container.
A more preferable embodiment of the fuel tank and the agricultural chemical container of the present invention is, from the inside to the outside, the ethylene polymer (α) layer (I) / adhesive layer (IV) / barrier layer (II) of the present invention. / A fuel tank and a pesticide container including a laminated structure composed of a regenerated layer (III).

  Further, in the fuel tank and the agricultural chemical container of the present invention, it is preferable that the ethylene polymer (α) layer (I) and the barrier layer (II) are laminated via an adhesive layer (IV). It is also preferable that the layer (III) and the barrier layer (II) are laminated via an adhesive layer.

  That is, in the fuel tank and the agricultural chemical container of the present invention, more preferably, the ethylene polymer (α) layer (I) / adhesive layer (IV) / barrier layer (II) / adhesive layer (IV) / regenerated layer ( III) / Ethylene polymer (α) layer (I) is a laminated structure. The regenerated layer is known as a crushed regenerated layer, and is preferably produced from so-called burr, which is generated in the form of material residue in the process of producing a hollow plastic product.

  The hollow molded article of the present invention is prepared by a conventionally known hollow molding (blow molding) method. There are various blow molding methods, and they are roughly classified into an extrusion blow molding method, a two-stage blow molding method, and an injection molding method. In the present invention, the extrusion blow molding method and the injection molding method are particularly preferably used.

Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.
[Measurement of ethylene polymer (α)]
The methods for measuring the physical properties of the ethylene polymer and the ethylene polymer (α) are shown below.

<Melt flow rate (MFR)>
According to JIS K7210 (1999), it was measured under the conditions of 190 ° C., 2.16 kg load and 190 ° C., 21.6 kg load.

<Density (d)>
According to JIS K7112 (1999), the strand obtained at the time of MFR measurement was heat-treated at 100 ° C. for 1 hour, left at room temperature for 1 hour, and then measured by a density gradient tube method.

<Melt tension (MT)>
The melt tension (MT) (unit: g) at 190 ° C. was determined by measuring the stress when stretched at a constant speed. A capillary rheometer: Capillograph 1B manufactured by Toyo Seiki Seisaku-sho, Ltd. was used for the measurement. The resin temperature was 190 ° C., the melting time was 6 minutes, the barrel diameter was 9.55 mmφ, the extrusion rate was 15 mm / min, the winding rate was 7.85 m / min, the die diameter was 2.095 mmφ, and the die length was 8 mm. It can be said that the larger this value is, the more the drawdown during hollow molding is suppressed, and the better the moldability is.

<Intrinsic viscosity [η]>
About 20 mg of the measurement sample was dissolved in 15 ml of decalin, and the specific viscosity η _sp was measured in an oil bath at 135 ° C. To this decalin solution, 5 ml of decalin solvent was added and diluted, and then the specific viscosity η _sp was measured in the same manner. This dilution operation was repeated twice more, and the value of η _sp / C when the concentration (C) was extrapolated to 0 as shown in the following formula (Eq-6A) was calculated as the intrinsic viscosity [η] (unit: dl / g ) As.
[Η] = lim (η _sp / C) (C → 0) -------- (Eq-6A)

<Number average molecular weight (Mn), weight average molecular weight (Mw), Z average molecular weight (Mz), Z + 1 average molecular weight (Mz + 1), molecular weight distribution (Mw / Mn, Mz / Mw, Mz + 1 / Mw)>
The molecular weight distribution curve was measured as follows using a gel permeation chromatograph alliance GPC2000 type (high temperature size exclusion chromatograph) manufactured by Waters.
Analysis software: Chromatography data system Empwer2 (Waters)
_{Column: TSKgel GMH 6 - HT × 2} + TSKgel GMH 6 -HTL × 2 ( inner diameter 7.5 mm × length 30 cm, Tosoh Corporation)
Mobile phase: o-dichlorobenzene (Wako Pure Chemicals special grade reagent)
Detector: Differential refractometer (built-in device)
Column temperature: 140 ° C
Flow rate: 1.0 mL / min Injection volume: 500 μL
Sampling time interval: 1 second Sample concentration: 0.15% (w / v)
Molecular weight calibration: Monodisperse polystyrene (Tosoh Corporation) / Molecular weight 495-200.6 million

Z. Crubisic, P.C. Rempp, H .; Benoit, J .; Polym. Sci. , B5 , 753 (1967), universal calibration was performed according to the procedure of general-purpose calibration, and number average molecular weight (Mn), weight average molecular weight (Mw), Z average molecular weight (Mz), as standard polyethylene molecular weight conversion, Z + 1 average molecular weight (Mz + 1) and molecular weight distribution (Mw / Mn, Mz / Mw, Mz + 1 / Mw) were determined.

<Shear pressure at 210 ° C (σ)>
The apparent shear pressure (σ) at 210 ° C. (unit: Pa) was determined by measuring the pressure when extruding at a constant rate. A capillary rheometer: Capillograph 1B manufactured by Toyo Seiki Seisaku-sho, Ltd. was used for the measurement. Conditions were resin temperature 210 ° C., barrel diameter 9.55 mmφ, extrusion rate 200 mm / min (apparent shear rate 19460 s ⁻¹ ), capillary length L was 5.0 mmφ, and diameter was 0.5 mm. .
It can be said that the larger this value is, the better the extensional flow characteristics are.

<Swell ratio>
The swell ratio at 230 ° C. was evaluated by a capillary rheometer manufactured by Toyo Seiki Seisakusho.
The barrel diameter was 9.55 mm, the length L of the thin tube was 3.0 mm, the diameter was 0.5 mm, and the inflow angle was 90 °.

  The sample was extruded at a cylinder temperature of 230 ° C. and a piston descending speed of 1 mm / minute, 2 mm / minute, and 5 mm / minute. When the piston descending speed was 2 mm / minute, a strand diameter (D i ) Was measured with a laser beam. The ratio (swell ratio = D i / D 0) between the strand diameter (D i) and the nozzle diameter (D 0) measured in this way was determined.

[Method for molding ethylene polymer (α), measurement of physical properties of hollow body]
<Blow molding conditions>
Using an NB-30 hollow molding machine manufactured by Japan Steel Works, Ltd., a hollow container was molded by an accumulator method, and the appearance was evaluated. Cylinder setting temperature: 210 ℃, Die setting temperature: 210 ℃, Mold temperature: 20 ℃, Injection speed: 0.1625kg / s, Die diameter: 132mm, Die gap: 5.25mm Parison is injected after parison is injected. It was cut open and the appearance of the inner surface and the outer surface of the parison was evaluated.
Further, the pinch shape of the molded bottle was confirmed by changing the gap of the die core according to the sample so that a 20 L square-shaped chemical can (with a bottle weight of 1000 g) was molded.

<Product skin / pinch shape>
Visually check the appearance of the parison and the pinch shape of the bottle,
a) A parison that has no sharkskin or spots, has an excellent appearance, and has a good pinch shape.
b) If the parison has no sharkskin, but the shape or pinch shape is bad, △
c) What causes sharkskin to occur in the parison ×
And

[Example 1]
[Synthesis example 1]
[Preparation of solid carrier (X-1)]
5 g of silica (average particle diameter = 3.8 μm, specific surface area = 804 m ² / g, pore volume = 0.87 mL / g) dried at 200 ° C. for 3 hours was suspended in 274 ml of toluene, and then suspended in methyl. 33.0 ml of an aluminoxane solution (Al = 3.03 mol / liter) was added dropwise over 30 minutes. Then, the temperature was raised to 100 ° C. over 1.5 hours, and the reaction was performed at that temperature for 4 hours. After that, the temperature was lowered to 60 ° C., and the supernatant was removed by the decantation method. The obtained solid catalyst component was washed three times with toluene and then resuspended in toluene to obtain a solid catalyst component (X-1) (total volume: 257 ml).

[Synthesis example 2]
[Preparation of solid catalyst component (Y-1) by supporting metallocene compound]
149.7 mL of dehydrated toluene was charged into a 500 mL glass container equipped with a magnetic stirrer and sufficiently replaced with nitrogen, and 54.28 mL (21 in terms of Al atom) of the toluene slurry of the solid carrier (X-1) prepared above was charged. .12 mmol). Then, 17.60 mL of a toluene solution of a transition metal complex represented by di (p-tolyl) methylene (cyclopentadienyl) (octamethyloctahydrodibenzofluorenyl) zirconium dichloride (A-1) (in terms of Zr atom) 0.047 mmol) was added dropwise, and 15 minutes later, 28.41 mL of a toluene solution of the transition metal complex represented by A-2 (0.026 mmol in terms of Zr atom) was added dropwise, and the mixture was reacted at room temperature for 1 hour. Then, an olefin polymerization catalyst (Y-1) was obtained.

<Ethylene polymer (α-1)>
250 L of purified heptane was placed in a polymerization tank having an internal volume of 500 liters that had been sufficiently replaced with nitrogen, and 89 mmol of triisobutylaluminum and 2.38 g of an olefin polymerization catalyst (Y-1) in terms of solid components were added thereto. After heating to 80 ° C and depressurizing once, ethylene / hydrogen mixed gas (gas phase concentration: hydrogen / ethylene = 0.100 (mol / mol)) is continuously supplied to obtain 0.65 MPa · G. It was supplied for 1 hour and polymerized for 1.9 hours. After the polymerization, the pressure was released, the atmosphere was replaced with nitrogen, and the ethylene / hydrogen mixed gas used was removed. The obtained polymer had a density of 963 (kg / m ³ ), [η] was 1.76 (dl / g), MFR was 2.01 g / 10 min, and the amount of polymerization of the polymer was 23.7 kg. there were.

  After inserting 60 mmol of triisobutylaluminum and 194 ml of 1-hexene into this polymerization tank, the temperature was raised to 75 ° C. and depressurized once, and then an ethylene / hydrogen mixed gas was continuously supplied to 0.30 MPa · G. (Concentration of gas phase: hydrogen / ethylene = 0.0091 (mol / mol)), and polymerization was carried out for 2.1 hours.

Methanol was added to the polymerization tank to stop the reaction, and cooling and residual gas were purged. The obtained slurry of ethylene polymer (PE) was filtered. The ethylene polymer was dried under reduced pressure at 80 ° C. for 10 hours. The obtained ethylene polymer was 36.4 kg, the polymerization activity was 124.7 kg-PE / mmol-Zr · hr, and the productivity was 3860 g-PE / g-cat. · Hr. As a result of analysis of the ethylene polymer, a powder having a bulk density of 0.479 g / cm ³ , a polymer density of 952 g / cm ³ , and an intrinsic viscosity [η] of 3.99 dL / g was obtained. The same operation was performed 3 times.

  To 100 parts by weight of the powder, 1000 ppm of Irganox 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.) and 1000 ppm of Irgafos 168 (manufactured by Ciba Specialty Chemicals Co., Ltd.) as a heat resistance stabilizer were blended at 1500 ppm of calcium stearate (manufactured by Nitto Kasei Kogyo Co., Ltd.). After that, using a single screw extruder manufactured by Placo (screw diameter 65 mm, L / D = 28, screen mesh 40/60/100/60/40), setting temperature of 240 ℃, resin extrusion rate of 25 (kg / hr) After melt-kneading under the conditions, it was extruded in a strand shape and cut to obtain pellets of the ethylene polymer (α-1). Table 1 shows the results of physical properties measurement using the obtained pellets as a measurement sample. Further, hollow molding was performed using the obtained pellets. Table 1 shows the product skin during molding.

[Example 2]
[Synthesis example 3]
[Preparation of solid carrier (X-2)]
9.0 kg of silica (average particle size = 3.8 μm, specific surface area = 804 m ² / g, pore volume = 0.87 mL / g) dried at 200 ° C. for 3 hours was suspended in 49.4 liters of toluene. After that, 59.4 liters of a methylaluminoxane solution (Al = 3.03 mol / liter) was added dropwise over 30 minutes. Then, the temperature was raised to 100 ° C. over 1.5 hours, and the reaction was performed at that temperature for 4 hours. After that, the temperature was lowered to 60 ° C., and the supernatant was removed by the decantation method. The obtained solid catalyst component was washed with toluene three times and then resuspended in toluene to obtain a solid catalyst component (X-2) (total volume 118 liters).

[Synthesis example 4]
[Preparation of solid catalyst component (Y-2) by supporting metallocene compound]
18.01 mol of the solid carrier (X-2) synthesized in Synthesis Example 1 suspended in toluene in a reaction vessel sufficiently replaced with nitrogen was converted into aluminum atom, and the suspension was stirred. Meanwhile, at room temperature (20 to 25 ° C.), 2 liters (40.38 mmoles) of the compound (A-1) 20.18 (mmoles / liter) solution was added and reacted for 0.25 hours. 2) (13.46 mmol) of a solution of 6.73 (mmol / l) was added to obtain an olefin polymerization catalyst (Y-2).

<Ethylene polymer (α-2)>
Hexane 29 (liter / hr), olefin polymerization catalyst (Y-2) converted to zirconium atom 0.027 (mmol / hr), ethylene 6.0 ( kg / hr), hydrogen 26.7 (N-liter / hr), and triisobutylaluminum 8.1 (mmol / hr) are continuously supplied, and ADEKA PRONIC L-71 (made by ADEKA Corporation, hereinafter L -71) 0.46 (g / hr) is continuously supplied, and while the polymerization contents are continuously withdrawn so that the liquid level in the polymerization tank is constant, the polymerization temperature is 80 ° C. and the reaction pressure is 0. Polymerization was carried out under the conditions of 0.52 (MPaG) and an average residence time of 3.7 hours.

The content continuously withdrawn from the first polymerization tank was subjected to removal of unreacted ethylene and hydrogen in a flash drum kept at an internal pressure of 0.30 (MPaG) and 60 ° C.
Then, the content, hexane 26 (liter / hr), triisobutylaluminum 6.2 (mmol / hr), ethylene 3.2 (kg / hr), hydrogen molecule were transferred to a second polymerization tank with an internal volume of 200 L equipped with a stirrer. 0.8 (N-liter / hr), 1-hexene 25 (g / hr) and L-71 0.24 (g / hr) were continuously supplied, and the liquid level in the polymerization tank was constant. Polymerization was carried out under the conditions of a polymerization temperature of 75 ° C., a reaction pressure of 0.30 (MPaG), and an average residence time of 2.1 hr while continuously extracting the polymerization content so that

Methanol was supplied to the contents withdrawn from the second polymerization tank at 2 (liter / hr) to deactivate the polymerization catalyst. Then, hexane and unreacted monomers in the contents were removed by a solvent separator and dried to obtain a polymer. The polymer obtained in the first polymerization tank had a density of 962 (kg / m ³ ), [η] of 1.80 (dl / g) and MFR of 1.83 g / 10 min. The operating conditions were adjusted so that the component polymerized in the first polymerization tank was 65% by weight and the component polymerized in the second polymerization tank was 35% by weight, and the density was 953 (kg / m ³ ), and [η] was A powder of 3.88 (dl / g) was obtained.

  To 100 parts by weight of the powder, 1000 ppm of Irganox 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.) and 1000 ppm of Irgafos 168 (manufactured by Ciba Specialty Chemicals Co., Ltd.) as a heat resistance stabilizer were blended at 1500 ppm of calcium stearate (manufactured by Nitto Kasei Kogyo Co., Ltd.). After that, using a single screw extruder manufactured by Placo (screw diameter 65 mm, L / D = 28, screen mesh 40/60/100/60/40), setting temperature of 240 ℃, resin extrusion rate of 25 (kg / hr) After melt-kneading under the conditions, it was extruded in a strand shape and cut to obtain pellets of an ethylene polymer (α-2). Table 1 shows the results of physical properties measurement using the obtained pellets as a measurement sample. Further, hollow molding was performed using the obtained pellets. Table 1 shows the product skin during molding.

[Example 3]
[Synthesis example 5]
[Preparation of solid catalyst component (Y-3) by supporting metallocene compound]
18.01 mol of the solid carrier (X-2) synthesized in Synthesis Example 1 suspended in toluene in a reaction vessel sufficiently replaced with nitrogen was converted into aluminum atom, and the suspension was stirred. Meanwhile, at room temperature (20 to 25 ° C.), 2 liters (40.38 mmoles) of the compound (A-1) 20.18 (mmoles / liter) solution was added and reacted for 0.25 hours. 2) (17.31 mmol) of 8.65 (mmol / l) solution was added to obtain an olefin polymerization catalyst (Y-3).

<Ethylene polymer (α-3)>
Hexane 28 (liter / hr), olefin polymerization catalyst (Y-3) 0.037 (mmol / hr) and ethylene 6.0 (kg) were converted to zirconium atoms in the first polymerization tank with an agitator having an internal volume of 340 L. / hr), hydrogen 28.7 (N-liter / hr) triisobutylaluminum 8.1 (mmol / hr), and L-71 at 0.46 (g / hr). Further, while continuously withdrawing the polymerization contents so that the liquid level in the polymerization tank becomes constant, polymerization was carried out under the conditions of a polymerization temperature of 80 ° C., a reaction pressure of 0.49 (MPaG), and an average residence time of 3.7 hr. It was

The content continuously withdrawn from the first polymerization tank was subjected to removal of unreacted ethylene and hydrogen in a flash drum kept at an internal pressure of 0.30 (MPaG) and 60 ° C.
Then, the content, hexane 25 (liter / hr), ethylene 3.2 (kg / hr), hydrogen 0.9 (N-liter / hr), 1-hexene were transferred to a second polymerization tank with an internal volume of 200 L equipped with a stirrer. Of 25 (g / hr), triisobutylaluminum (6.2) (mmol / hr) and L-71 (0.24 (g / hr)) were continuously supplied, and the liquid level in the polymerization tank was kept constant. Polymerization was carried out under the conditions of a polymerization temperature of 75 ° C., a reaction pressure of 0.29 (MPaG), and an average residence time of 2.1 hr while continuously extracting the polymerization content.

Methanol was supplied to the contents withdrawn from the second polymerization tank at 2 (liter / hr) to deactivate the polymerization catalyst. Then, hexane and unreacted monomers in the contents were removed by a solvent separator and dried to obtain a polymer. The polymer obtained in the first polymerization tank had a density of 963 (kg / m ³ ), [η] of 1.51 (dl / g), and MFR of 4.63 g / 10 min. The operating conditions were adjusted so that the component polymerized in the first polymerization tank was 69% by weight and the component polymerized in the second polymerization tank was 31% by weight, and the density was 956 (kg / m ³ ), and [η] was 3.70 (dl / g) powder was obtained.

  To 100 parts by weight of the powder, 1000 ppm of Irganox 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.) and 1000 ppm of Irgafos 168 (manufactured by Ciba Specialty Chemicals Co., Ltd.) as a heat resistance stabilizer were blended at 1500 ppm of calcium stearate (manufactured by Nitto Kasei Kogyo Co., Ltd.). After that, using a single screw extruder manufactured by Placo (screw diameter 65 mm, L / D = 28, screen mesh 40/60/100/60/40), setting temperature of 240 ℃, resin extrusion rate of 25 (kg / hr) After melt-kneading under the conditions, it was extruded into a strand and cut to obtain pellets of the ethylene polymer (α-3). Table 1 shows the results of physical properties measurement using the obtained pellets as a measurement sample. Further, hollow molding was performed using the obtained pellets. Table 1 shows the product skin during molding.

[Example 4]
<Ethylene polymer (α-4)>
Hexane 29 (liter / hr), olefin polymerization catalyst (Y-3) 0.034 (mmol / hr), ethylene (5.2 kg) / hr), hydrogen 30.1 (N-liter / hr), triisobutylaluminum 8.1 (mmol / hr), and L-71 0.44 (g / hr) are continuously supplied, and the polymerization tank is used. Polymerization was carried out under the conditions of a polymerization temperature of 80 ° C., a reaction pressure of 0.42 (MPaG), and an average residence time of 3.8 hr, while continuously extracting the polymerization contents so that the liquid level inside was constant.

The content continuously withdrawn from the first polymerization tank was subjected to removal of unreacted ethylene and hydrogen in a flash drum kept at an internal pressure of 0.30 (MPaG) and 60 ° C.
Then, the content, hexane 25 (liter / hr), ethylene 4.0 (kg / hr), hydrogen molecule 1.4 (N-liter / hr), 1- Hexene 25 (g / hr), triisobutylaluminum 6.2 (mmol / hr), L-71 0.26 (g / hr) were continuously supplied, and the liquid level in the polymerization tank was kept constant. Polymerization was carried out under the conditions of a polymerization temperature of 75 ° C., a reaction pressure of 0.37 (MPaG), and an average residence time of 2.1 hr while continuously extracting the polymerization contents.

Methanol was supplied to the contents withdrawn from the second polymerization tank at 2 (liter / hr) to deactivate the polymerization catalyst. Then, hexane and unreacted monomers in the contents were removed by a solvent separator and dried to obtain a polymer. The polymer obtained in the first polymerization tank had a density of 963 (kg / m ³ ), [η] of 1.58 (dl / g) and MFR of 3.02 g / 10 min. The operating conditions were adjusted so that the component polymerized in the first polymerization tank was 65% by weight and the component polymerized in the second polymerization tank was 35% by weight, and the density was 953 (kg / m ³ ), and [η] was 3.80 (dl / g) powder was obtained.

  To 100 parts by weight of the powder, 1000 ppm of Irganox 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.) and 1000 ppm of Irgafos 168 (manufactured by Ciba Specialty Chemicals Co., Ltd.) as a heat resistance stabilizer were blended at 1500 ppm of calcium stearate (manufactured by Nitto Kasei Kogyo Co., Ltd.). After that, using a single screw extruder manufactured by Placo (screw diameter 65 mm, L / D = 28, screen mesh 40/60/100/60/40), setting temperature of 240 ℃, resin extrusion rate of 25 (kg / hr) After melt-kneading under the conditions, it was extruded in a strand shape and cut to obtain pellets of the ethylene polymer (α-4). Table 1 shows the results of physical properties measurement using the obtained pellets as a measurement sample. Further, hollow molding was performed using the obtained pellets. Table 1 shows the product skin during molding.

[Example 5]
<Ethylene polymer (α-5)>
Hexane 28 (liter / hr), olefin polymerization catalyst (Y-3) 0.037 (mmol / hr) and ethylene 6.0 (kg) were converted to zirconium atoms in the first polymerization tank with an agitator having an internal volume of 340 L. / hr), hydrogen 28.7 (N-liter / hr) triisobutylaluminum 8.1 (mmol / hr), L-71 is continuously fed at 0.46 (g / hr). Further, while continuously withdrawing the polymerization contents so that the liquid level in the polymerization tank becomes constant, polymerization was carried out under the conditions of a polymerization temperature of 80 ° C., a reaction pressure of 0.49 (MPaG), and an average residence time of 3.7 hr. It was

The content continuously withdrawn from the first polymerization tank was subjected to removal of unreacted ethylene and hydrogen in a flash drum kept at an internal pressure of 0.30 (MPaG) and 60 ° C.
Then, the content, hexane 25 (liter / hr), ethylene 3.2 (kg / hr), hydrogen 0.9 (N-liter / hr), 1-hexene were transferred to a second polymerization tank with an internal volume of 200 L equipped with a stirrer. 40 (g / hr), triisobutylaluminum 6.2 (mmol / hr), L-71 0.24 (g / hr) are continuously supplied, and the liquid level in the polymerization tank becomes constant. Polymerization was carried out under the conditions of a polymerization temperature of 75 ° C., a reaction pressure of 0.29 (MPaG), and an average residence time of 2.1 hr while continuously extracting the polymerization content.

Methanol was supplied to the contents withdrawn from the second polymerization tank at 2 (liter / hr) to deactivate the polymerization catalyst. Then, hexane and unreacted monomers in the contents were removed by a solvent separator and dried to obtain a polymer. The polymer obtained in the first polymerization tank had a density of 963 (kg / m ³ ), [η] of 1.51 (dl / g) and MFR of 4.61 g / 10 min. The operating conditions were adjusted so that the component polymerized in the first polymerization tank was 69% by weight and the component polymerized in the second polymerization tank was 31% by weight, and the density was 951 (kg / m ³ ), and [η] was 3.70 (dl / g) powder was obtained.

  To 100 parts by weight of the powder, 1000 ppm of Irganox 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.) and 1000 ppm of Irgafos 168 (manufactured by Ciba Specialty Chemicals Co., Ltd.) as a heat resistance stabilizer were blended at 1500 ppm of calcium stearate (manufactured by Nitto Kasei Kogyo Co., Ltd.). After that, using a single screw extruder manufactured by Placo (screw diameter 65 mm, L / D = 28, screen mesh 40/60/100/60/40), setting temperature of 240 ℃, resin extrusion rate of 25 (kg / hr) After melt-kneading under the conditions, it was extruded in a strand shape and cut to obtain pellets of an ethylene polymer (α-5). Table 1 shows the results of physical properties measurement using the obtained pellets as a measurement sample. Further, hollow molding was performed using the obtained pellets. Table 1 shows the product skin during molding.

[Comparative Example 1]
[Synthesis example 6]
[Preparation of solid catalyst component (Y-4) by supporting metallocene compound]
18.01 mol of the solid catalyst (X-2) synthesized in Synthesis Example 1 suspended in toluene in a reaction vessel sufficiently replaced with nitrogen was converted into aluminum atom, and the suspension was stirred. Then, at room temperature (20 to 25 ° C.), 2 liters (61.12 mmol) of the compound (A-1) 31.06 (mmol / liter) solution was added and reacted for 1 hour to obtain an olefin polymerization catalyst (Y-4). Obtained.

<Ethylene polymer (β-1)>
In a first polymerization tank with an internal volume of 340 L equipped with a stirrer, hexane 51 (liter / hr), olefin polymerization catalyst (Y-4) was converted to zirconium atom 0.027 (mmol / hr), ethylene 7.8 (kg). / hr), hydrogen 29.1 (N-liter / hr), triisobutylaluminum 11.2 (mmol / hr), L-71 0.46 (g / hr) are continuously supplied, and the polymerization tank Polymerization was carried out under the conditions of a polymerization temperature of 80 ° C., a reaction pressure of 0.75 (MPaG), and an average residence time of 2.7 hr while continuously extracting the polymerization content so that the liquid level in the solution was constant.

The content continuously withdrawn from the first polymerization tank was subjected to removal of unreacted ethylene and hydrogen in a flash drum kept at an internal pressure of 0.30 (MPaG) and 60 ° C.
Then, the content, hexane 26 (liter / hr), ethylene 4.2 (kg / hr), hydrogen 0.7 (N-liter / hr), 1-hexene were transferred to a second polymerization tank with an internal volume of 200 L equipped with a stirrer. 35 (g / hr), triisobutylaluminum 7.2 (mmol / hr) and L-71 0.24 (g / hr) are continuously supplied, and the liquid level in the polymerization tank becomes constant. Polymerization was carried out under the conditions of a polymerization temperature of 75 ° C., a reaction pressure of 0.26 (MPaG) and an average residence time of 1.6 hr while continuously extracting the polymerization content.

Methanol was supplied to the contents withdrawn from the second polymerization tank at 2 (liter / hr) to deactivate the polymerization catalyst. Then, hexane and unreacted monomers in the contents were removed by a solvent separator and dried to obtain a polymer. The polymer obtained in the first polymerization tank had a density of 965 (kg / m ³ ), [η] of 1.17 (dl / g), and MFR of 13 g / 10 min. The operating conditions were adjusted so that the component polymerized in the first polymerization tank was 65% by weight and the component polymerized in the second polymerization tank was 35% by weight, and the density was 953 (kg / m ³ ), and [η] was A powder of 3.55 dl / g) was obtained.

  To 100 parts by weight of the powder, 1000 ppm of Irganox 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.) and 1000 ppm of Irgafos 168 (manufactured by Ciba Specialty Chemicals Co., Ltd.) as a heat resistance stabilizer were blended at 1500 ppm of calcium stearate (manufactured by Nitto Kasei Kogyo Co., Ltd.). After that, using a single screw extruder manufactured by Placo (screw diameter 65 mm, L / D = 28, screen mesh 40/60/100/60/40), setting temperature of 240 ℃, resin extrusion rate of 25 (kg / hr) After melt-kneading under the conditions, it was extruded in a strand shape and cut to obtain pellets of the ethylene polymer (β-1). Table 1 shows the results of physical properties measurement using the obtained pellets as a measurement sample. Further, hollow molding was performed using the obtained pellets. Table 1 shows the product skin during molding.

Ethylene polymer of Comparative Example 1, the shear rate at 210 ° C. of the ethylene-based polymer (β-1) 19460s ^- pressure at ¹ (sigma, Pa) is smaller than the right side of the requirements [c]. As a result, the shark's skin had a poor appearance on the product skin.

[Comparative Example 2]
<Ethylene polymer (β-2)>
In a first polymerization tank with an internal volume of 340 L equipped with a stirrer, hexane 51 (liter / hr), olefin polymerization catalyst (Y-4) was converted into zirconium atoms of 0.027 (mmol / hr), and ethylene was 7.2 ( kg / hr), hydrogen 26.1 (N-liter / hr), triisobutylaluminum 11.2 (mmol / hr) L-71 0.46 (g / hr) are continuously fed and polymerized. Polymerization was carried out under conditions of a polymerization temperature of 80 ° C., a reaction pressure of 0.75 (MPaG), and an average residence time of 2.7 hr while continuously extracting the polymerization content so that the liquid level in the tank was constant.

The content continuously withdrawn from the first polymerization tank was subjected to removal of unreacted ethylene and hydrogen in a flash drum kept at an internal pressure of 0.30 (MPaG) and 60 ° C.
Then, the content, hexane 26 (liter / hr), ethylene 4.8 (kg / hr), hydrogen 0.8 (N-liter / hr), 1-hexene were transferred to a second polymerization tank with an internal volume of 200 L equipped with a stirrer. 35 (g / hr), triisobutylaluminum 7.2 (mmol / hr) and L-71 0.24 (g / hr) are continuously supplied, and the liquid level in the polymerization tank becomes constant. Polymerization was carried out under the conditions of a polymerization temperature of 75 ° C., a reaction pressure of 0.26 (MPaG) and an average residence time of 1.6 hr while continuously extracting the polymerization content.

Methanol was supplied to the contents withdrawn from the second polymerization tank at 2 (liter / hr) to deactivate the polymerization catalyst. Then, hexane and unreacted monomers in the contents were removed by a solvent separator and dried to obtain a polymer. The polymer obtained in the first polymerization tank had a density of 964 (kg / m ³ ), [η] of 1.34 (dl / g), and MFR of 7.2 g / 10 min. The operating conditions were adjusted so that the component polymerized in the first polymerization tank was 60% by weight and the component polymerized in the second polymerization tank was 40% by weight, and the density was 952 (kg / m ³ ), and [η] was 3.46 (dl / g) of powder was obtained.

  To 100 parts by weight of the powder, 1000 ppm of Irganox 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.) and 1000 ppm of Irgafos 168 (manufactured by Ciba Specialty Chemicals Co., Ltd.) as a heat resistance stabilizer were blended at 1500 ppm of calcium stearate (manufactured by Nitto Kasei Kogyo Co., Ltd.). After that, using a single screw extruder manufactured by Placo (screw diameter 65 mm, L / D = 28, screen mesh 40/60/100/60/40), setting temperature of 240 ℃, resin extrusion rate of 25 (kg / hr) After melt-kneading under the conditions, it was extruded into a strand and cut to obtain pellets of an ethylene polymer (β-2). Table 1 shows the results of physical properties measurement using the obtained pellets as a measurement sample. Further, hollow molding was performed using the obtained pellets. Table 1 shows the product skin during molding.

Ethylene polymer of Comparative Example 2, the shear rate at 210 ° C. of the ethylene-based polymer (β-2) 19460s ^- pressure at ¹ (sigma, Pa) is smaller than the right side of the requirements [c]. As a result, the shark's skin had a poor appearance on the product skin.

[Comparative Example 3]
[Synthesis example 7]
[Preparation of solid catalyst component (Y-5) by supporting transition metal complex]
142.7 mL of dehydrated toluene was charged into a 500 mL glass container equipped with a magnetic stirrer and sufficiently replaced with nitrogen, and the toluene slurry of the solid carrier (X-1) prepared above was 43.00 mL (16 Al in terms of Al atom). 0.74 mmol). Next, 64.30 mL of a toluene solution of a transition metal complex represented by A-2 (0.058 mmol in terms of Zr atom) was added dropwise and reacted at room temperature for 1 hour to obtain an olefin polymerization catalyst (Y-5). It was

<Ethylene polymer (β-3)>
250 L of purified heptane was placed in a polymerization tank having an internal volume of 500 liters which was sufficiently replaced with nitrogen, and 89 mmol of triisobutylaluminum and 1.86 g of an olefin polymerization catalyst (Y-5) in terms of solid components were added thereto. After heating to 80 ° C and depressurizing once, ethylene / hydrogen mixed gas (gas phase concentration: hydrogen / ethylene = 0.120 (mol / mol)) is continuously added so that the pressure becomes 0.50 MPa · G. Was continuously supplied and polymerization was carried out for 2.5 hours. After the polymerization, the pressure was released, the atmosphere was replaced with nitrogen, and the ethylene / hydrogen mixed gas used was removed. The obtained polymer had a density of 964 (kg / m ³ ), [η] of 1.36 (dl / g), MFR of 6.42 g / 10 min, and a polymerized amount of 22.4 kg. It was

  Insert 60 mmol of triisobutylaluminum and 194 ml of 1-hexene into this polymerization tank, raise the temperature to 75 ° C and depressurize once, then continuously supply ethylene / hydrogen mixed gas to 0.65 MPa · G. (Concentration of gas phase part: hydrogen / ethylene = 0.011 (mol / mol)), and polymerization was carried out for 1.4 hours.

Methanol was added to the polymerization tank to stop the reaction, and cooling and residual gas were purged. The obtained slurry of ethylene polymer (PE) was filtered. The ethylene polymer was dried under reduced pressure at 80 ° C. for 10 hours. The obtained ethylene polymer was 34.5 kg, the polymerization activity was 152.5 kg-PE / mmol-Zr · hr, and the productivity was 4760 g-PE / g-cat. · Hr. As a result of analysis of the ethylene polymer, a powder having a bulk density of 0.453 g / cm ³ , a polymer density of 959 g / cm ³ , and an intrinsic viscosity [η] of 6.19 dL / g was obtained. The same operation was performed 3 times.

  To 100 parts by weight of the powder, 1000 ppm of Irganox 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.) and 1000 ppm of Irgafos 168 (manufactured by Ciba Specialty Chemicals Co., Ltd.) as a heat resistance stabilizer were blended at 1500 ppm of calcium stearate (manufactured by Nitto Kasei Kogyo Co., Ltd.). After that, using a single screw extruder manufactured by Placo (screw diameter 65 mm, L / D = 28, screen mesh 40/60/100/60/40), setting temperature of 240 ℃, resin extrusion rate of 25 (kg / hr) After melt-kneading under the conditions, it was extruded in a strand shape and cut to obtain pellets of the ethylene polymer (β-3). Table 1 shows the results of physical properties measurement using the obtained pellets as a measurement sample. Further, hollow molding was performed using the obtained pellets. Table 1 shows the product skin during molding.

  The ethylene-based polymer of Comparative Example 3 did not generate sharkskin because it satisfied the requirement [c], but the swell ratio of the requirement [e] was small and it was difficult to control the molding of the parison. In addition, since the requirement [h] of Mw / Mn is not satisfied, there is a problem that it is assumed that the dispersion is poor, and the pinch-off part of the parison joint (the fusion-bonded part between the parison and the mold) becomes thin, resulting in a pinch. The shape has deteriorated.

[Comparative Example 4]
Table 1 shows the results of measurements of physical properties performed in the same manner as in Example 1 except that high-density polyethylene "Nipolon Hard 8900" manufactured by Tosoh Corporation was used as the ethylene-based polymer. Further, hollow molding was performed. Table 1 shows the product skin during molding.
The ethylene polymer of Comparative Example 4 has a Charpy impact strength ( kJ / m ² ) at −40 ° C. smaller than the right side of the requirement [d], and therefore has insufficient impact resistance when dropped.

[Comparative Example 5]
Table 1 shows the results of physical properties measurement performed in the same manner as in Example 1 except that high-density polyethylene "HI-ZEX8200B" manufactured by Prime Polymer Co., Ltd. was used as the ethylene polymer. Further, hollow molding was performed. Table 1 shows the product skin during molding.
The ethylene polymer of Comparative Example 5 has a Charpy impact strength ( kJ / m ² ) at −40 ° C. smaller than the right side of the requirement [d], and therefore has insufficient impact resistance when dropped.

[Comparative Example 6]
Table 1 shows the results of physical properties measurement performed in the same manner as in Example 1 except that high-density polyethylene "4261AG" manufactured by Basell was used as the ethylene-based polymer. Further, hollow molding was performed. Table 1 shows the product skin during molding.
The ethylene polymer of Comparative Example 6 has a Charpy impact strength ( kJ / m ² ) at −40 ° C. smaller than the right side of the requirement [d], and thus has insufficient impact resistance when dropped.

[Comparative Example 7]
Table 1 shows the results of physical properties measurement performed in the same manner as in Example 1 except that high-density polyethylene "HB111R" manufactured by Nippon Polyethylene Corporation was used as the ethylene-based polymer. Further, hollow molding was performed. Table 1 shows the product skin during molding.
Ethylene polymer of Comparative Example 7, since the Charpy impact strength at -40 ℃ (kJ / m ²⁾ is smaller than the right side of the requirements [d], the impact resistance during dropping is insufficient.

[Reference Example 1]
[Synthesis example 8]
[Preparation of solid catalyst component (Y-6) by supporting transition metal compound]
149.7 mL of dehydrated toluene was charged into a 500 mL glass container equipped with a magnetic stirrer and sufficiently replaced with nitrogen, and 54.28 mL (21 in terms of Al atom) of the toluene slurry of the solid carrier (X-1) prepared above was charged. .12 mmol). Then, 17.60 mL (0.047 mmol in terms of Zr atom) of a toluene solution of a transition metal complex represented by the compound (A-1) was charged dropwise, and the mixture was reacted at room temperature for 1 hour to obtain an olefin polymerization catalyst (Y-6). ) Got.

<Ethylene polymer (γ-1)>
250 L of purified heptane was placed in a polymerization tank having an internal volume of 500 liters which was sufficiently replaced with nitrogen, and 89 mmol of triisobutylaluminum and 2.38 g of an olefin polymerization catalyst (Y-6) in terms of solid components were added thereto. After that, polymerization was carried out under the same conditions as in Example 1. The polymer obtained during the 80 ° C. (first stage) polymerization had a density of 969 (kg / m ³ ) and an intrinsic viscosity [η] of 0.92 (dl / g), and the polymerization amount of the polymer was 12. It was 5 kg, the polymerization activity was 88.1 kg-PE / mmol-Zr · hr, and the productivity was 2760 g-PE / g-cat. · Hr.

Then, polymerization was carried out at 75 ° C. (second stage), the polymerization activity was 66.5 kg-PE / mmol-Zr · hr, and the productivity was 2030 g-PE / g-cat. · Hr. The intrinsic viscosity [η] of the polymer obtained after the completion of the polymerization was 3.23 dL / g, the polymerization amount of the polymer was 22.4 kg, and the polymerization activity was 77.2 kg-PE / mmol-Zr · hr. The productivity was 2380 g-PE / g-cat..hr.
From the intrinsic viscosities [η] at the first stage and after the polymerization, the intrinsic viscosity [η] of the high molecular weight component of the ethylene copolymer polymerized at the second stage was 6.15 (dl / g).

[Reference example 2]
[Synthesis example 9]
[Preparation of solid catalyst component (Y-7) by supporting transition metal compound]
149.7 mL of dehydrated toluene was charged into a 500 mL glass container equipped with a magnetic stirrer and sufficiently replaced with nitrogen, and 54.28 mL (21 in terms of Al atom) of the toluene slurry of the solid carrier (X-1) prepared above was charged. .12 mmol). Then, 28.41 mL of a toluene solution of a transition metal complex represented by the compound (A-2) (0.026 mmol in terms of Zr atom) was charged dropwise, and the mixture was reacted at room temperature for 1 hour to obtain an olefin polymerization catalyst (Y-7). ) Got.

<Ethylene polymer (γ-2)>
250 L of purified heptane was placed in a polymerization tank having an internal volume of 500 liters which was sufficiently replaced with nitrogen, and 89 mmol of triisobutylaluminum and 2.38 g of an olefin polymerization catalyst (Y-7) in terms of solid components were added thereto. After that, polymerization was carried out under the same conditions as in Example 1. The polymer obtained during the 80 ° C. (first stage) polymerization had a density of 953 (kg / m ³ ) and an intrinsic viscosity [η] of 2.30 (dl / g), and the polymerization amount of the polymer was 11. The polymerization activity was 28.9 kg, the polymerization activity was 78.9 kg-PE / mmol-Zr · hr, and the productivity was 2470 g-PE / g-cat. · Hr.

  Then, polymerization was carried out at 75 ° C. (second stage), the polymerization activity was 18.0 kg-PE / mmol-Zr · hr, and the productivity was 560 g-PE / g-cat. · Hr. The intrinsic viscosity [η] of the polymer obtained after the completion of the polymerization was 5.44 dL / g, the polymerization amount of the polymer was 14.0 kg, the polymerization activity was 47.0 kg-PE / mmol-Zr · hr, The productivity was 1460 g-PE / g-cat..hr.

From the intrinsic viscosity [η] at the first stage and after the polymerization, the intrinsic viscosity [η] of the high molecular weight component of the ethylene copolymer polymerized at the second stage was 18.0 (dl / g).
From Reference Example 1 and Reference Example 2, the intrinsic viscosity [η] of the high molecular weight component of the ethylene copolymer polymerized with the transition metal compound (A-1) at 75 ° C. (second stage) in Example 1 was 6. 1 (dl / g), the amount of polymerization was 27.5% by weight of the total amount, and an ethylene copolymer polymerized with the transition metal compound (A-2) at 75 ° C. (second stage) in Example 1. The intrinsic viscosity [η] of the high molecular weight component of 1 is 18.0 (dl / g), and the polymerization amount is 7.5% by weight of the total amount.

Claims (9)

An ethylene polymer (α) which simultaneously satisfies the following requirements [a], [b], [c], [d], [e] and [f] .
[a] Melt flow rate (HLMI) at a temperature of 190 ° C. and a load of 21.6 kg is in the range of 1.0 to 10 g / 10 minutes,
[b] The density is in the range of 945 to 965 kg / m ³ ,
[c] Using a die having a length of 5.0 mm and a diameter of 0.5 mm, the relationship between the pressure (σ, Pa) and the HLMI at a shear rate of 19460 s ⁻¹ at 210 ° C. is in the following range,
log (σ) ≧ −0.12 × log (HLMI) +7.65
[d] The relationship between Charpy impact strength (kJ / m ² ) at −40 ° C. measured according to JIS K7111 and HLMI is the following inequality (Eq-2-3) and inequality (Eq−) below. 2-4) is simultaneously satisfied.
log (Charpy impact strength) ≧ −1.1 × log (HLMI) +2.20 ... (Eq-2-3)
log (Charpy impact strength) ≧ 1.6 (Eq-2-4) ”
[e] The swell ratio measured at 230 ° C. is in the range of 1.56 or more.
[f] In the environmental stress crack resistance test (ESCR test; test temperature 65 ° C., test piece thickness 3 mmt) measured according to ASTM D1693, the 50% crack generation time (F ₅₀ ) is 300 hours or more. Furthermore, the ethylene-based polymer (α) according to claim 1, which satisfies the following requirement [g].
[g] In a tensile creep test (test temperature of 80 ° C.) measured according to JIS K7115, when the test stress is 6 MPa, the creep strain after 100 hours is 15% or less. The ethylene polymer (α) according to claim 1 or 2, which further satisfies the following requirement [h].
[h] Mw / Mn and Mz ₊₁ / Mw determined by gel permeation chromatography (GPC) measurement are in the following ranges.
4.0 ≦ (Mw / Mn) ≦ 22.0 and (Mz ₊₁ /Mw)≧16.0 Ethylene polymer (alpha) is an ethylene-based polymer according to any one of claims 1 to 3, which is a hollow molded article (alpha). Hollow molded body containing a layer comprising the ethylene polymer (alpha) according to any one of claims 1-3. A fuel tank, a kerosene can, a drum, a container for chemicals, a container for agricultural chemicals, a container for solvents, or a bottle, which is composed of the hollow molded article according to claim 5 . A laminated structure comprising a layer (I) comprising the ethylene polymer (α) according to any one of claims 1 to 5 , an adhesive layer (IV), a barrier layer (II) and a regenerating layer (III). A fuel tank or a pesticide container, which is composed of a hollow molded body. The fuel tank or the agricultural chemical container according to claim 7 , wherein the layer (I) made of the ethylene polymer (α) and the barrier layer (II) are laminated via the adhesive layer (IV). . The fuel tank or the agricultural chemical container according to claim 7 or 8 , wherein the barrier layer (II) comprises an ethylene-vinyl alcohol copolymer.